Joomla integration with credit cards

The site that I'm looking to add credit card processing to is based on Joomla.  It's funny that of all the the credit card sales people that have called me, none have asked the basic questions that most matter.  Mostly, we want the technology to work smoothly.

There is a joomla component called AEC which is developed (I'm not kidding) by the GlobalNerds.

  It's likely we'll use AEC as our integration module.  So, for our initial credit card processor, we're likely to pick whichever one the AEC people (who are going to the implementation for us) suggests as the simplest.  

AEC is a component that handles integration with subscriptions and payment processing.   Later, to keep costs low as our sales rise, we'll switch to Google Checkout (if they maintain their deal to credit adsense marketing expenses against credit card fees)